It will pass. I went on an insane binge of this and 3-meo-pcp a few years ago. I was pretty much using every day for about 4 months. I had depersonalization/derealization, my mind seemed to stop working for a couple months after. I utilized Pramiracetam to speed up recovery from that episode and it allowed me to start feeling grounded again, AMPAkine's seem to be capable of reversing some of the effects of dissociatives even blocking a lot of the high if you use it with Ketamine or MXE. It is completely recoverable however. Just be patient, if you are having delusions just confront them and don't be afraid to ask questions and see what is real or just perceived. It's tough but just remain patient and know that it WILL pass and you will be normal again.
MXE is insanely addictive, I tried some recently with the intention to just use it as an anti-depressant. I did a couple doses and flushed the rest. I was just honest with myself and knew that I would only end up going on a binge and ruin my transition onto relative sobriety on Suboxone. The intention was to do a couple hole doses and utilize the anti-depressant glow that follows but this chemical is way too addictive to be able to maintain control and use it responsibly. I used 100mgs of 2 and a half grams which cost me a bit of money at the time but it was most certainly worth it to flush it. There are many people out there who can use and put down drugs with their own free will but that definitely is not me. I'm really glad that I did flush it.. NMDA antagonists do have an amazing capacity to relieve depression. I have a friend who underwent supervised Ketamine transfusions for his tratment resistant depression and after 3 sessions in 6 months, he no longer is affected with depression. These were 1 hour blood transfusions so the dose is monitored and just enough is used to have the intended effect and the effects are long lasting and there doesn't seem to be any upkeep needed. If one continued to abuse drugs afterward they would likely encounter depression again.
While these substances have amazing healing potential, the dose makes the poison and abuse can have the opposite effect. Time and just finding ways to remain grounded and understand what is irrational and what is not. If you absolutely cannot stand it than anti-psychotics may be able to help you, they come with some potentially horrible side effects but if you need them, you need them. If it is just temporary damage from methoxetamine abuse than it will pass and medication may not be necessary but in some cases dissociative and psychedelic drugs can awaken latent mental illness but only time can tell if that is the case. The benzodiazepines were probably a bad idea because once you get dependant on them, coming off of them you will have worsened anxiety so you also have that to contend with. It definitely didn't help your situation. You could try something that Works on GABA but isn't necessarily a narcotic for relief from thise symptoms, Ashwaghanda root extract is a light anxiolytic but it will provide some relieef without causing dependance.
AMPAkine Racetams are what helped me when I experienced this problem after my massive binge a few years ago.. Racetams seem to block the effects of dissociatives while using bith at the same time. This has something to do with AMpA receptors and NMDA antagonism. I had reasoned that it would help with my depersonalization ad withdrawal from dissociatives and it seemed to help tremendously for me. I used Pramiracetam which is a much stronger ampakine than what I am currently using, Aniracetam but Aniracetam may be more beneficial because it's metabolite n-anisoyl-gaba acts as an anxiolytic as well. It could help you achieve more lucidity as well as help abate the anxiety and frustration/bewilderment that comes with derealization/depersonalization.
I hope this helps somewhat. I have been in this same situation before and this is what helped me.